An arsonist proves to be a tough adversary for Worcester's sleuths September 1143. Serjeant Catchpoll hopes a fire at a Worcester silversmith's is just an accident, but when a charred corpse is discovered following a second fire, he has no choice but to call in the undersheriff. Hugh Bradecote may be new to the job compared to his wily colleague, but his analytical eye is soon hard at work. With further fires and a hooded figure stalking the streets, the duo must piece together the arsonist's vengeful motive.